With most of what you mentioned, the local quacker is not able to say "OMG YOU GOT CANCER, HERE TAKE THIS $1000/pill HOMEOPATHIC CRAP"... with an ultrasound image he is very well able to do so. And people
will do it, thanks to human greed - if you need a confirmation google for "miracle mineral supplement" aka chlorine dioxide and the "industry" surrounding this.
This is why we can't have nice things, the potential of abuse is just too high :(